Conventional fire detection systems in aircraft engines rely on fire detection switches disposed within electrical fire detection circuits. In isolation, such fire detection switches are circuit components connected to common and alarm pins connected to sources of electric current. Such conventional fire detection switches are normally open, so that current does not flow through them in ‘normal’, or operating, conditions, but is directed through a path having a resistor. When a fire detection switch is for example exposed to high temperatures associated with fire, the switch closes to complete the circuit and bypasses the path with a resistor. However, if a short circuit occurs through, for example, damage to the switch, a defect in the switch, or other circuit damage, the same bypassing of the path with a resistor can occur, and may result in a false alarm of fire. Conventional fire detection circuits are not capable of distinguishing between a true fire detection signal and a false signal caused by a short circuit.